Many diesel engine fuel systems employ low cost, reliable, piston-type fuel transfer pumps that create large flow pulsations in the fuel line downstream from the pump. While these pulsations have no adverse affect upon the performance of the fuel system or the engine, they can have a very detrimental effect upon the accuracy of a flow transducer used to measure the rate of fuel flow to the engine.
To accurately measure fuel flow in diesel fuel systems that include piston-type transfer pumps, it is necessary either to damp the flow pulsations, or to protect the flow transducers from the pulsations with a bypass diaphragm or equivalent device. However, the bypass approach is impractical in many diesel engine applications because the pulsation volumes are too large.